1. Field of the Invention
The present invention relates to an improvement on a hydraulic device for elevating/lowering a chair of barbering/beautification or dentistry, particularly of barbering, whose seat part's elevation is performed through technician's stepping on an operation lever which is for stepping on at the time of performance of technique, said hydraulic device controlling elevation and descent of the chair through stepping on of the operation lever.
2. Description of the Related Art
Regarding a conventional chair, for example, regarding a chair of barbering/beautification, there are a chair in which hydraulic fluid is supplied to a hydraulic cylinder, utilizing a pump of an electric pump and a chair in which hydraulic fluid is supplied to a hydraulic cylinder, through stepping on the above-mentioned operation lever by a foot. Regarding an elevating/lowering device for a chair in which the electric pump is utilized, for example, there is a device described in Japanese Utility Model Application Laid-Open No. H4-52634. In such a device in which a chair is elevated through such an electric pump, a seat part is elevated to a desired position continuously since hydraulic fluid is supplied to the hydraulic cylinder continuously by means of the pump. Accordingly, such a device has not given a shock to a seating person who receives technician's work while the seat is being elevated.
On the other hand, in a case of a simple chair in which hydraulic fluid is supplied from an oil tank through stepping on an operation lever by a foot (which is popularly adopted for beauty treatment, for example, in a case of a chair which is introduced in a web site of the present applicant company, since hydraulic fluid for one time is supplied from a hydraulic cylinder to an elevating/lowering cylinder through one time stepping, it is necessary to step on the operation lever a plurality of times to elevate a person who receives technician's work to a desired height position.
In the device in which oil is supplied to the elevating/lowering cylinder through stepping on the operation lever by a foot, since the oil supply to the elevating/lowering cylinder is stopped every time the operation lever is stepped, there is a problem that the seat part is stopped every time oil supply to the hydraulic cylinder is stopped so that such a device gives shock to the person who receives technician's work and gives him/her an uncomfortable feeling.